Mr price *****

I settled the account in December 2019 I requested it to be closed. Was given a form to sign and they said they will email it to their head offices instead of doing that they ported my number and bought R1000 airtime on my name and account was never closed its still active and they have blacklisted me, I find out when I was trying to buy a house for my kids. Please help me out I don't know what to do anymore